Systems and methods for extracting analytes from a sample

ABSTRACT

Systems and methods for extracting an analyte from a sample. The system includes a reaction vessel for receiving the sample and a reaction solution, a mixer for mixing the sample with the reaction solution, a filter and a drain for passing soluble components from the reaction mixture, including the dissolved analyte, from the reaction vessel. A purification vessel is located below the reaction vessel. A selective sorbent is disposed in the purification vessel for retaining contaminants from the soluble components from the reaction mixture and passing a purified analyte. An evaporation container is located below the purification vessel. A heater heats the evaporation chamber and evaporates the solvents from the purified analyte, which can then be quantitatively measured.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuing application of U.S. National PatentApplication Ser. No.: Ser. No. 16/977,717, now U.S. Pat. No. 10,989,634,entitled “SYSTEMS AND METHODS FOR EXTRACTING ANALYTES FROM A SAMPLE” andfiled Sep. 2, 2020, which is a 371 National Application of PCTInternational Application No.: PCT/US2020/030369, filed Apr. 29, 2020,which further claims priority to a U.S. Provisional Patent ApplicationSer. No. 62/840,110 filed Apr. 29, 2019 entitled “INSTRUMENT AND METHODFOR ISOLATION OF ANALYTES THROUGH RELEASE, EXTRACTION, PURIFICATION, ANDCONCENTRATION”. The contents of the aforementioned applications arehereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention is directed to systems and methods that performvarious chemical and physical operations resulting in the automatedextraction of an analyte in preparation for quantitative measurement.

BACKGROUND

The extraction (i.e., isolation) and quantitation of certain nutrientsfrom complex matrices can be challenging, particularly from naturalsources. In the early 1900s the government started mandating testing offoods through the Pure Food and Drug Act. More recently, with the adventof the 1990 Nutrient Labeling and Education Act (NLEA), the Food andDrug Administration has required food manufacturers to provide nutrientinformation to consumers. Such nutrient information is provided in theform of a nutrition label on all packaged foods. As a consequence of theNLEA, food manufacturers are required to analyze their products so thataccurate information about the nutrient content can be provided tocustomers.

Analysis of any food or feed product requires several initial orpreliminary processes designed to chemically release, purify, andconcentrate target analytes (select nutrients) from the physical andchemical matrices of the product. That is, before the analyte can beidentified and quantitated by high performance liquid chromatography(HPLC) or gas chromatography (GC), the hydrogen, ionic and/or covalentbonds which bind the analyte to its physical and/or chemical matrix mustbe broken and sufficient quantities must be collected.

Historically, these analytical processes have been performed manually inan analytical laboratory by skilled laboratory technicians. Morespecifically, these processes have been performed to quantitativelyextract analytes, such as fat soluble vitamins (FSVs), leading to finalquantitation by either spectrophotometry or more recently HPLC. FSVsmust be extracted in a non-polar solvent fraction that is free fromwater soluble compounds and most lipids. For example, the analysis ofretinol (Vitamin A) most commonly involves: (i) the cleavage of esterlinkages through saponification, (ii) removal of water-soluble compoundsand extraction of the analyte by bi-phase separation, and (iii)concentration of the resultant analyte by evaporation of the solvent.The analysis is complicated by a requirement to conduct each stepwithout exposure to selective wavelengths of light and in the absence ofoxygen.

Other major impediments to the analysis are formation of emulsionsduring bi-phase separations. Emulsions effectively forms a third phasethat is hard to separate and which prohibits complete extraction of theanalyte. Most emulsions will settle over time. If emulsions arepersistent, an additional step, such as centrifugation or re-extraction,may be needed to break the emulsion and fully extract the analyte. Theseare costly analytical steps.

Another example where several initial or preliminary processes arerequired to chemically release, purify, and concentrate target analytesis the analysis of total fat. The steps involved includes: (i)hydrolysis in a hydrochloric acid (HCl) solution, (ii) removal of watersoluble compounds in a bi-phase separation of an aqueous phase andorganic solvent phase (in a Mojonnier flask), and (iii) evaporation ofsolvent for gravimetric quantitation of isolated fat. In other total fatmethods, fat can be captured by oleophilic filters while allowing theaqueous solution to pass through. The residue and filter then must bethoroughly dried before extraction with organic solvents. The dryingstep removes trace water from the hydrolyzed sample which subsequentlyenables the non-polar solvent to penetrate the otherwise polarhydrolyzed sample. After extraction, the solvent containing the fat isevaporated and the isolated fat is quantitated gravimetrically. It willbe appreciated that these methods are time-consuming, fiscallyburdensome, and labor intensive.

In view of the difficulties and complexities of the current methodsassociated with the extraction of the analytes (e.g., FSV and total fat)there is a need for a self-contained, fully-automated system and methodfor extracting analytes from complex samples.

SUMMARY

Systems and methods for extracting an analyte from a sample aredisclosed. In one embodiment, the system includes a reaction chambercomprising a reaction vessel having a column for receiving the sampleand a reaction solution, a mixer for mixing the sample with the reactionsolution, a filter and a drain for passing soluble components, includingthe dissolved analyte, from the reaction vessel.

In one embodiment, a purification chamber is located below the reactionchamber and includes a purification vessel having a column for receivingthe dissolved analyte from the reaction vessel. A selective sorbent isdisposed in the purification vessel for retaining contaminants from thesoluble components from the reaction mixture and passing a purifiedanalyte.

An evaporation chamber is located below the purification chambercomprising an evaporation container for receiving the purified analytecontained in solvent from the purification vessel. A heater heats theevaporation chamber and evaporates the solvents from the purifiedanalyte, which can then be transferred for quantitative measurement.

The above embodiments are exemplary only. Other embodiments are withinthe scope of the disclosed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the invention briefly summarized abovemay be had by reference to the embodiments, some of which areillustrated in the accompanying drawings. It is to be noted, however,that the appended drawings illustrate only typical embodiments of thisinvention and are therefore not to be considered limiting of its scope,for the invention may admit to other equally effective embodiments.Thus, for further understanding of the nature and objects of theinvention, references can be made to the following detailed description,read in connection with the drawings in which:

FIG. 1 depicts a perspective view of an exemplary automated system orextractor for extracting analytes for quantitative measurement;

FIG. 2 depicts a schematic, profile view of the exemplary system shownin FIG. 1 including a reaction chamber, a shuttle valve transferapparatus, a purification chamber, and an evaporation chamber;

FIG. 3 depicts a perspective view of the exemplary reaction vessels,purification vessels, and evaporation containers in parallel;

FIG. 4 depicts a schematic, exploded view of the exemplary componentsassociated with a single station of the system, including a reactionchamber, a shuttle valve transfer apparatus, a purification chamber, andan evaporation chamber;

FIG. 5 depicts an enlarged schematic view of a portion of the exemplaryreaction vessel;

FIG. 6 depicts a schematic, exploded view of an exemplary purificationvessel;

FIG. 7A depicts a sectional view taken substantially along line 7A-7Adepicting the shuttle valve in a closed position;

FIG. 7B depicts a sectional view taken substantially along line 7B-7Bdepicting the shuttle valve in an open-to-vessel position; and

FIG. 7C is a sectional view taken substantially along line 7C-7Cdepicting the shuttle valve in an open-to-waste position.

DETAILED DESCRIPTION

The present disclosure is directed to an analyte extractor (orinstrument) configured to automatically extract (i.e., isolate) analytesfrom complex matrices for subsequent quantitative analysis by, e.g.,chromatography, spectrophotometry or gravimetric measurement. While theexemplary analyte extractor is principally configured to extract (i.e.,isolate) fats and fat-soluble analytes, it should be appreciated thatthe device is equally applicable to any device having as its principlefunction, the liberation, extraction, purification and isolation ofanalytes which must be separated from complex matrices. Furthermore,while the exemplary analyte extractor includes a variety ofchambers/vessels/containers/processes, in series, for isolating analytesfor subsequent quantitative analysis, it will be appreciated that otherembodiments may utilize fewer chambers/vessels/containers/processes toproduce samples for further testing. For example, the analyte extractormay not utilize the evaporation chamber to produce an analyte forsubsequent analysis. Moreover, while the exemplary instrument includesas many as four assay stations/positions a, b, c, d in parallel, i.e.,in juxtaposed relation, for performing extraction processes on four (4)complex samples, it will be appreciated that the analyte extractor mayutilize any number of assay stations or positions to extract analytefrom samples.

FIG. 1 depicts an exemplary analyte extractor 10 in accordance with theteachings of the present disclosure that includes a body or chassis 12that allows for the fixed and detachable mounting of various componentsof the extractor 10. The exemplary analyte extractor 10 comprises aplurality of vertically aligned chambers including a reaction chamber100, which is located above a purification chamber 200, which is locatedabove an evaporation chamber 300 for mounting one or more likecomponents, i.e., components performing the same or similar operation.

Samples (e.g., food or feedstuff samples) can be deposited into andreceived by one or more reaction vessels 104 a, 104 b, 104 c, 104 d inthe reaction chamber 100. As used herein, the term “vessel” generallyrefers to, e.g., a column, tube, etc. that can contain a fluid and allowthe fluid to pass through. As used herein, the term column and tube areused interchangeably. A mixture of various solutions can be added to thesamples in the reaction vessels 104 a, 104 b, 104 c, 104 d after whichagitating (e.g., mixing) can be performed, and heat can be added, toaccomplish a first function where a dissolved analyte of the sample isproduced in the soluble components of the reaction mixture. Thedissolved analyte flows serially down through a filter, to one or moredetachable purification vessels (e.g., columns, tubes, etc.) 204 a, 204b, 204 c, 204 d associated with the purification chamber 200 that arevertically aligned along a same axis and below the respective reactionvessels 104 a, 104 b, 104 c, 104 d, such that a second operation can beperformed to produce a purified analyte contained in solvent. Similarly,the purified analyte contained in solvent in the second row orpurification chamber 200 can flow serially down to one or morecontainers (e.g., flasks) 304 a, 304 b, 304 c, 304 d in yet another rowassociated with the evaporation chamber 300 that are vertically alignedalong the same axis and below the respective purification vessels 204 a,204 b, 204 c, 204 d, such that yet another operation can be performed.

In the described embodiment, the analyte extractor 10 may comprise aplurality of columns/stations/lanes a, b, c, d for integrating aplurality of vessels (e.g., columns, tubes, etc.) and containers (e.g.,flasks) in parallel. As such, a plurality of samples, corresponding tothe number of stations, can be processed simultaneously, vastlyincreasing throughput. Control inputs to the analyte extractor 10 may bemade through a display, command, input or touch screen 22. All variablesassociated with a method or a process may be input through thedisplay/screen 22. Each of these system components and method steps willbe discussed in greater detail in the subsequent paragraphs.

FIGS. 2, 3 and 4 depict detailed schematics of the exemplary analyteextractor 10 of the present disclosure depicting the relevant internaldetails and components of the instrument. More specifically, pumps P canbe associated with valves V and flow meters M to inject a volume ofliquid/solution into the reaction vessels 104 a, 104 b, 104 c, 104 d ofthe reaction chamber 100. In one embodiment, a diffusing nozzle can belocated at the inlets of the reaction vessels 104 a, 104 b, 104 c, 104 dto deflect the pumped solution toward an internal wall of the reactionvessel to wash down and dissolve analyte material disposed along theinternal wall of the reaction vessel.

A heater H can be operative to heat the sample/mixture within one ormore of the chambers 100, 300 effectively forming an oven in eachchamber 100, 300. A blower B can be operative to circulate air withinone or more of the chambers 100, 300. One or more temperature sensors T1and T2 control temperature in chambers 100, 300. Temperature sensors STmay also be provided in, on or integrated with, the reaction vessels 104a, 104 b, 104 c, 104 d to provide temperature feedback in closeproximity to, or within, the sample analyte being processed/evaluated.

One or more actuators A may be used to open/close a ganged shuttle valve150 at appropriate intervals in the analyte extraction process. Aplurality of reservoirs R_(L1), R_(L2), R_(L3), R_(L4) and correspondingvalves V may be employed for combining the various solutions with thesample within at least the reaction chamber 100. Furthermore, while inthe exemplary embodiment, each of the reservoirs R_(L1), R_(L2), R_(L3),R_(L4) includes a valve V, it will be appreciated that a single valve Vmay be used to control the flow associated with two or more reservoirsR_(L1), R_(L2), R_(L3), R_(L4). A processor 20, such as amicroprocessor, can be operative to control all processes within thesystem. Similarly, while a single processor 20 is shown to control theoperations associated with each of the chambers, 100, 200, 300, it willbe appreciated that several microprocessors may be employed to controlindependent functions of the analyte extractor 10. Finally, a powersource (not shown) can be used to activate the pumps P, heater H, blowerB, valves V, actuator A, temperature sensors ST, T1, and T2, pressuresensor Sp, liquid sensors SL, ganged shuttle valve 150 and processor 20of the analyte extractor 10. Similarly, the pumps P, valves V, and flowmeters M are operatively coupled to the processor 20 such that anaccurate flow and quantity of solutions contained in fluid reservoirsR_(L1), R_(L2), R_(L3), R_(L4), may be supplied to the reaction vessels104 a, 104 b, 104 c, 104 d.

Reaction Chamber

The analyte extractor 10 performs a variety of critical operations toisolate the target analytes from the complex sample. In the firstprocess, i.e., in the reaction chamber 100, a sample can be exposed toone or more solutions, while being agitated and heated in an oxygen-freeenvironment. This step releases the target analyte from a complexmatrix. Fat soluble vitamin analysis typically releases the vitaminsthrough an ethanolic saponification reaction, while total fat analysistypically releases fat through a HCl hydrolysis reaction. Thesereactions result in an analyte which can be dissolved in a complexmixture of solutions along with an insoluble residue. This mixture canbe filtered before it is passed onto the purification vessels (thesecond chamber 200 of the analyte extractor or instrument 10).

The reaction vessel 104 has a unique design that allows for theseparation of the liquid portion from the insoluble residue. Tofacilitate the discussion, a single reaction vessel 104 a will bedescribed in detail with the understanding that adjacent reactionvessels 104 b, 104 c, 104 d can be essentially identical and do notrequire or warrant additional description. Hence, when referring to onereaction vessel in the reaction chamber 100 and/or one componentassociated with the purification and evaporation chambers 200, 300, itshould be understood that the vessel or step being described can applyto all of the same components associated with an adjacent assay station.The reaction vessel 104 a can be removable so that it can be placed on abalance/scale and sample can be weighed directly into the vessel 104 a.

The reaction vessel 104 a can be chemically inert and designed towithstand strong acids, bases, and organic solvents at temperaturesranging from, e.g., between 20° C. to 105° C. Prior to reaction, thereaction vessel 104 a can be closed (e.g., automatically closed) bylowering a chemically inert reaction vessel cap (i.e., lid, plug, top,etc.) 108 a over and enclosing the top opening of the vessel 104 a. Eachreaction vessel cap 108 a may contain temperature and pressure sensorsST, SP, and apertures (i.e., ports, apertures, orifices, etc.) 112 a forvent and liquid supply lines. The reaction vessel 104 a can becompletely sealed, and with feedback from each of these sensors, providecomplete control of the internal environment. To protect sensitiveanalytes, such as vitamin A and E, an oxygen-free environment can becreated in the reaction vessel by inserting an inert gas such asnitrogen (N₂) gas.

Each reaction vessel 104 a can be detachable to facilitate removal,cleaning, sterilization and loading of sample material (not shown). Thereaction vessel 104 a can comprise a cylindrically shaped reactionvessel column 106 a made of, e.g., borosilicate glass, a reaction vesselcap 108 a having a plurality of apertures 112 a, and a detachablereaction vessel base 110 a. It will be understood that the scope of theinvention includes reaction vessels 104 a having a shape different thana cylindrical column. In addition to receiving temperature and pressuresensors ST, SP, the apertures 112 a may receive fluids or ventgases/volatiles from the reaction vessel 104 a sample mixture. A liquidsensor SL may be provided through the top or bottom of each vessel orcontainer to ensure that liquids have drained or evaporated from therespective vessel or container. For example, in FIG. 4 , the reactionvessel 104 a may include a liquid sensor SL through the detachablereaction vessel base 110 a to indicate when fluids have drained from thereaction vessel 104 a. Alternatively, or additionally, a liquid sensorSL may be disposed in the flexible tubing between the reaction vesseldrain (e.g., a drain) 116 a and the shuttle valve 150. When therefractive index changes, the liquid sensor SL can determine that liquidis no longer present in the tube, hence, no longer remaining in thereaction vessel 104 a.

While the exemplary borosilicate glass reaction vessel column 106 a canbe configured to be cleaned, sanitized and reused, it will beappreciated that other materials may be employed which are disposable.For example, a transparent polypropylene cylindrical column may beemployed with built-in components to facilitate rapid deployment andreuse of a reaction vessel 104 a. That is, a disposable reaction vessel104 a may include the reaction vessel cap 108 a having apertures 112 afor receiving the temperature sensor ST, the pressure sensor Sp, and oneor more fluid fill lines. The disposable vessel 104 a may also includethe reaction vessel base 110 a including the mixer driver 132 a, mixingstir bar 130 a, the requisite reaction vessel filter 140 a, and areaction vessel drain 116 a. An O-ring seal may or may not be requiredinasmuch as other sealing methods may be employed and the reactionvessel base 110 a may or may not be detachable.

In the described embodiment, the reaction vessel cap 108 a can be fixedto the instrument and be able to apply a downward force to seal thereaction vessel cap 108 a, the reaction vessel column 106 a, and thedetachable reaction vessel base 110 a of the reaction vessel 104 a. Thereaction vessel cap 108 a includes at least two apertures 112 a disposedin fluid communication with at least one of the fluid reservoirs R_(L1),R_(L2), R_(L3), R_(L4), and at least one supply of nitrogen gas (N₂).Nitrogen gas N₂ may be injected into the reaction vessel 104 a toproduce an oxygen-free or oxygen-starved environment. As such,evaporating solvents cannot form a combustible gas inasmuch as thesolvent-to-oxygen ratio can be maintained below combustion levels. Theback pressure from the nitrogen gas (N₂) can also function to facilitateflow of the dissolved analyte through the particulate reaction vesselreaction vessel filter 140 a and the reaction vessel drain 116 a.

The vessel caps 108 a may be fabricated from a plastic. In oneembodiment, the plastic can be a polytetrafluoroethylene polymer,commonly known as a Teflon material (Teflon® is a registered Trademarkof E.I. du Pont de Nemours and Company, located in Wilmington, State ofDelaware). Since the vessel caps 108 a are exposed to large temperaturevariations, i.e., between room temperature to over one-hundred degreesCelsius (100° C.), the effect of thermal expansion must be considered toensure a gas- and fluid-tight seal with the reaction vessel column 106a. With respect to the reaction vessel cap 108 a, an elastomer or rubberO-ring can be sealed between the wall surface of the reaction vesselcolumn 106 a and the reaction vessel cap 108 a. This arrangement andgeometry can improve seal integrity since the sealing interface can becompressed due to the difference in thermal growth, or coefficient ofthermal expansion, between the plastic vessel cap 108 a and theborosilicate glass reaction vessel column 106 a.

FIG. 5 shows a detailed diagram of the reaction vessel base 110 a. Thereaction vessel base 110 a can also be fabricated from apolytetrafluoroethylene polymer or plastic material (e.g., Teflon®). TheO-ring seal 118 a can be disposed between the outer peripheral surface122 a of the reaction vessel column 106 a and the inner wall of thereaction vessel base 110 a. Inasmuch as the growth of the plasticreaction vessel base 110 a could be greater than the borosilicate glassreaction vessel column 106 a, an outer ring or sleeve 114 a ofreinforcing material may surround the plastic reaction vessel base 110 ato restrict its outward growth. The material selected for fabricatingthe outer ring or sleeve 114 a should have a lower coefficient ofthermal expansion than the plastic reaction vessel base 110 a, andpreferably, a similar rate of thermal expansion of the borosilicateglass. In the described embodiment, the outer ring or sleeve 114 a canbe fabricated from a metal, such as stainless steel. As a consequence,the seal integrity may be maintained or improved by an inwardly directedradial force 124 a applied by the metal outer ring 114 a. To improveseal integrity yet further, the O-ring seal 118 a is received within agroove 120 a having a substantially dove-tailed cross-sectionalgeometry. This configuration captures the O-ring seal 118 a as thereaction vessel column 106 a slides into, and received within, thecavity of the plastic reaction vessel base 110 a. That is, the dove-tailgroove 120 a maintains the efficacy of the sealing interface along theouter peripheral surface 122 a of the reaction vessel column 106 a,especially during assembly of the plastic reaction vessel base 110 a.

The reaction vessel 104 a can include a mixing stir bar 130 a andconcentric mixer driver 132 a, which can be mounted below the reactionvessel base 110 a, and operative to mix fluids with the sample in thereaction vessel 104 a. More specifically, the mixing system comprises amixing stir bar 130 a and a mixer driver 132 a coaxially aligned. Thereaction vessel drain 116 a of the reaction vessel base 110 a can bealigned with and in fluid communication with an extraction port 117 aformed within a housing of the mixer driver 132 a. Furthermore, anO-ring 134 a can be disposed at the interface of the reaction vesseldrain 116 a of the reaction vessel 104 a and the extraction port 117 aof the mixer driver 132 a to provide a fluid seal during operation. Thisdesign allows a drain to exit at the bottom of the reaction vessel base110 a.

A high torque mixing system is preferred inasmuch as when combiningcertain samples and chemical solutions, reactions occur thatsignificantly increase viscosity. In addition, the mixing system must besufficiently robust to completely mix bi-phase solutions within alimited diameter vessel. The mixer motor has the ability to vary speedand direction, thus enabling the magnet to break free and spin underhighly viscous conditions. The mixing stir bar 130 a can be magnetic,i.e., has a north and south pole, which repels or attracts relative tothe poles produced by the magnetic mixer driver 132 a. Morespecifically, the mixer driver 132 a can define a torus-shapedelectrical winding circumscribing the extraction port 117 a and createsan alternating magnetic flux field for driving the mixing stir bar 130 aabout a rotational axis. The mixing stir bar 130 a agitates the sampleas one or more saponification fluids or solvents are added to thereaction vessel 104 a.

In the described embodiment, the mixer driver 132 a portion of the mixer130 a, 132 a can be disposed below the reaction vessel 104 a and outsidethe reaction chamber 100, which can form an oven when heated. As aconsequence, the mixer driver 132 a is unaffected by the heat of thereaction chamber 100. Additionally, the current-driven magnetic mixerdriver 132 a cannot produce an electrical spark in the reaction chamber100 which may contain combustible gases as a consequence of the use ofsolvents, such as ethanol or hexane, in the reaction chamber 100.

The reaction vessel 104 a can be disassembled into a reaction vesselcolumn 106 a and reaction vessel base 110 a which allows for theplacement of a reaction vessel filter 140 a therebetween. Thecompressive force exerted by the reaction vessel cap 108 a seals andsecures the perimeter of the reaction vessel filter 140 a, such thatparticulates cannot circumvent the reaction vessel filter 140 a. Theselective reaction vessel filter 140 a is capable of filtering insolubleparticulate matter from the dissolved analyte material. Morespecifically, the reaction vessel filter 140 a separates liquids fromsolids when performing a vitamin analysis. Furthermore, when performinga fat analysis, the reaction vessel filter 140 a quantitatively retainsthe lipid fractions while removing unwanted aqueous fractions to waste.

The reaction vessel filter 140 a can function as a temporary valve whenthe reaction vessel 104 a is removed from the reaction chamber 100,filled with sample material, and weighed. That is, since the reactionvessel 104 a must contain a dry or wet sample while being loaded,weighed and, subsequently, reassembled into the reaction chamber 100,the reaction vessel filter 140 a prevents the sample, or a portion ofthe sample, from escaping through the reaction vessel drain 116 a. Thereaction vessel filter 140 a may vary in composition depending upon thechemical resistance properties and the type of analysis being performed.

For example, when performing a fat analysis on a food sample, thereaction vessel filter 140 a can be fabricated from a filter mediahaving the capacity to retain particles two microns (2 μm) and larger.Typically, the reaction vessel filter 140 a will range from betweenapproximately two microns (2 μm) to approximately fifteen microns (15μm) when performing such analyses. When performing a vitamin analysis,the filter media of the reaction vessel filter 140 a can be fabricatedfrom a filter material having a pore size less than approximately eightmicrons (8 μm). Typically, the filter media of the reaction vesselfilter 140 a will range from between about eight microns (8 μm) to aboutthirty microns (30 μm). The retention of particulate when performingvitamin analyses does not need to be comprehensive. While it isimportant that fines do not clog fine tubing and valves, it is notcritical that all fines are retained in the reaction vessel filter 140 abecause contrary to fat analysis, the entire saponified mixture ofliquid and ultrafine particles are transferred to the purificationvessel 204 a. The purification vessel 204 a not only retains the polarcompounds but also filters out any fine particles that pass through thereaction vessel filter 140 a.

Shuttle Valve

It will be appreciated that while the reaction is occurring in thereaction vessel 104 a, the sample and dissolved analyte remain in thereaction chamber 104 a for a prescribed period (e.g., a dwell period).In one embodiment, a timer is provided to determine a dwell timeassociated with the operation of, e.g., the mixer, pump, and heat sourceand providing a dwell signal indicative of the operating time of each.

In the described embodiment, this can be accomplished by a shuttle valve150 a, which prevents the gravitational flow of the dissolved analytefrom the reaction vessel 104 a for the prescribed dwell period. FIGS.7A-7C depict schematic sectional views along the length and through eachof the ports 156 a-156 d, 157 a-157 d, 158 a-158 d of the shuttle valve150 in different configurations of the shuttle valve 150. Arrows 7A-7A,7B-7B, 7C-7C as shown in FIG. 3 illustrate the direction of thecross-sectional plane and do not provide information concerning thekinematics of the shuttle valve operation. As will be appreciated uponreview of the subsequent paragraphs, the plates 152, 154 of the shuttlevalve 150 slide orthogonally relative to the direction of arrows 7A-7A,7B-7B, 7C-7C.

In FIGS. 3 and 7A-7C, the shuttle valve 150 can comprise a pair ofsliding plates, i.e., an upper or first plate 152, and a lower or secondplate 154, wherein the first plate 152 includes ports 156 a, 156 b, 156c, 156 d which are horizontally spaced in the plane of the plate 152.The plates 152, 154 are interposed between the reaction vessel drains116 a, 116 b, 116 c, 116 d of the respective reaction vessels 104 a, 104b, 104 c, 104 d and the input ports 202 a, 202 b, 202 c, 202 d of therespective purification vessels 204 a, 204 b, 204 c, 204 d.

Examination of configuration of the plates 152, 154 shown in FIG. 7A(closed position) reveals that the ports 156 a, 156 b, 156 c, 156 d ofthe first plate 152 are dead-ended or closed against the upper surfaceof the second plate 154. Accordingly, the shuttle valve 150 is in aclosed position for inhibiting the passage of dissolved analyte from thereaction vessel drains 116 a, 116 b, 116 c, 116 d of the respectivereaction vessels 104 a, 104 b, 104 c, 104 d to the input ports 202 a,202 b, 202 c, 202 d of the respective purification vessels 204 a, 204 b,204 c, 204 d.

Examination of configuration of the plates 152, 154 shown in FIG. 7Breveals that shuttle valve 150 is in a open-to-waste positionfacilitating the passage of fluid through the first and second plates152, 154 by means of the aligned port pairs 156 a, 157 a, 156 b, 157 b,156 c, 157 c, 156 d, 157 d in plates 152, 154, respectively. That is,the actuator A moves the relative position of the plates 152, 154 suchthat the ports 156 a, 156 b, 156 c, 156 d from one plate 152 align withthe ports 157 a, 157 b, 157 c, 157 d of the opposing plate 154. It willbe appreciated that the input ports 156 a, 156 b, 156 c, 156 d arealigned with output ports 157 a, 157 b, 157 c, 157 d located on thelower plate 154 to allow the flow of fluid from the reaction vessels 104a, 104 b, 104 c, 104 d across the plates 152, 154 towards a drainreservoir. This can be achieved by moving the second or lower plate 154in one direction, e.g., in the direction of arrow L to the left (FIG.7B), while maintaining the position of the upper plate 152, i.e., heldstationary. In another embodiment, the second or lower plate 154 canremain stationary while the first or upper plate 152 moves to the right.Potential uses of the drain-to-waste position are to remove solventvapors from the reaction vessel or to remove unnecessary liquids fromthe reaction vessel.

Examination of configuration of the plates 152, 154 shown in FIG. 7Creveals that shuttle valve 150 is in a open-to-vessel (purification)position facilitating the passage of fluid through the first and secondplates 152, 154 by means of the aligned port pairs 156 a, 158 a, 156 b,158 b, 156 c, 158 c, 156 d, 158 d in plates 152, 154, respectively. Thatis, the actuator A moves the relative position of the plates 152, 154such that the ports 156 a, 156 b, 156 c, 156 d from one plate 152 alignwith the output ports 158 a, 158 b, 158 c, 158 d of the opposing plate154. It will be appreciated that the input ports 156 a, 156 b, 156 c,156 d are aligned with output ports 158 a, 158 b, 158 c, 158 d locatedon the lower plate 154 to allow the flow of dissolved analyte from thereaction vessels 104 a, 104 b, 104 c, 104 d across the plates 152, 154to the respective purification vessels 204 a, 204 b, 204 c, 204 d. Thiscan be achieved by moving the second or lower plate 154 in onedirection, e.g., in the direction of arrow R to the right (FIG. 7C),while maintaining the position of the upper plate 152, i.e., heldstationary. In another embodiment, the second or lower plate 154 canremain stationary while the first or upper plate 152 moves to the left.Accordingly, the shuttle valve simultaneously controls the flow betweenthe reaction vessels 104 a, 104 b, 104 c, 104 d and the purificationvessels 204 a, 204 b, 204 c, 204 d.

The low-profile geometry of the shuttle valve 150 allows the valve 150to be mounted below the reaction chamber 100 while remaining in closeproximity to the reaction vessel drains 116 a, 116 b, 116 c, 116 d ofthe reaction vessels 104 a, 104 b, 104 c, 104 d. Moreover, the use of asmall inner-diameter tubing to connect the reaction vessel drains 116 a,116 b, 116 c, 116 d to the purification vessels 204 a, 204 b, 204 c, 204d ensures a minimal air gap therebetween. This ensures that liquid doesnot migrate into the valve area when the reaction chamber 100 isoperational. Finally, the shuttle valve 150 can be pneumaticallyactuated reducing the potential for electrical sparks in areas which maycontain evaporated solvent and potentially flammable/combustible gases.

Purification Chamber

In the purification chamber 200, the analyte extractor 10 separateswanted fractions of the dissolved analyte from reaction vessel 104 afrom unwanted fractions of the dissolved analyte from reaction vessel104 a by passing the dissolved analyte through a purification vessel 204a filled with a selective sorbent 216 a (e.g., a solid phase filtermaterial, such as siliceous earth, also commonly referred to asdiatomaceous earth (DE) or other chromatographic media or aluminumoxide). Before passing the dissolved analyte through the purificationvessel 204, the selective sorbent can be conditioned to retain polarcompounds in the purification vessel 204 while permitting the morenon-polar target analytes to pass through the purification vessel 204.This can be achieved by passing a specific quantity of water and ethanolthrough the selective sorbent, either prior to or simultaneously withthe sample.

As shown in FIGS. 1, 3, and 6 , the purification chamber 200 defines acavity for mounting four (4) purification vessels 204 a, 204 b, 204 c,204 d which can be arranged substantially horizontally across thepurification chamber 200. Continuing with the description above, asingle purification vessel 204 a will be described with theunderstanding that adjacent vessels 204 b, 204 c, 204 d can beessentially identical and do not require or warrant additionaldescription. Hence, when referring to one purification vessel 204 a inthe purification chamber 200, it should be understood that the vesselbeing described applies to all of the vessels in the adjacent assaystations.

The purification vessel 204 a can be configured to receive the dissolvedanalyte from the reaction vessel 104 a following the reaction andfiltration of the analyte in the reaction chamber 100. Morespecifically, the purification vessel 204 a can be in fluidcommunication with the reaction vessel drain 116 a of the reactionvessel 104 a though a shuttle valve 150.

The purification vessel 204 a includes a polymer (e.g., polypropylene)cylindrically shaped purification vessel column 208 a having apurification vessel drain (e.g., a tapered nozzle) 210 a at one end anda top opening 212 a at the other end, equivalent in size to the diameterof the purification vessel column 208 a. It will be understood that thescope of the invention includes purification vessel 204 a having a shapedifferent than a cylindrical column. While, in the disclosed embodiment,the purification vessel 204 a can be a polymer, it should also beunderstood that the purification vessel 204 a could be any flexible orrigid single use container.

The purification vessel column 208 a can be configured to receive: (i)lower purification vessel filter 214 a for being disposed above thepurification vessel drain 210 a, (ii) a volume of a selective sorbent(e.g., siliceous earth (SE)) 216 a, (iii) a purification vessel diffuser218 a, and (iv) a purification vessel cap (i.e., lid, plug, top, etc.)220 a for controlling the flow of dissolved analyte and nitrogen intothe purification vessel column 208 a. The lower purification vesselfilter 214 a and purification vessel diffuser 218 a are employed to holdthe selective sorbent 216 a without allowing any of the filter materialthrough the purification vessel filter 214 a or the purification vesseldiffuser 218 a. The pores of the lower purification vessel filter 214 aand the purification vessel diffuser 218 a must be sufficiently small tohold the selective sorbent material.

The dissolved analyte from the reaction vessel 104 a enters thepurification vessel column 208 a via the reaction vessel cap apertures224 a in the purification vessel cap 220 a. In one embodiment and asshown in FIG. 3 , an input port 202 a can feed the mixture from thereaction vessel drain 116 a to the purification vessel cap 220 a of thepurification vessel column 208 a. Once through the reaction vessel capaperture 224 a, the purification vessel diffuser 218 a diffuses orspreads the analyte solution to prevent the formation of flow channels,(similar to erosion caused by running water) through the selectivesorbent 216 a. As such the analyte material is spread in a substantiallyuniform manner over the top of the selective sorbent 216 a. Once thedissolved analyte from the reaction vessel 104 a is passed through thepurification vessel 204 a, the purified analyte contained in solventflows serially through the purification vessel drain 210 a to one ormore containers (e.g., flasks) 304 a, 304 b, 304 c, 304 d in theevaporation chamber 300.

Evaporation Chamber to Evaporate Liquids from the Purified AnalyteMaterial

In the evaporation chamber 300, the solvent can be evaporated from thepurified analyte such that the purified analyte may be collected forsubsequent quantitation (e.g., by HPLC or GC). In FIG. 4 , theevaporation container (e.g., flask) 304 a is in fluid communicationwith, and receives, the purified analyte material from the purificationvessel 204 a, i.e., from the purification vessel drain 210 a. It will beunderstood that the scope of the invention includes evaporationcontainers 304 a having a shape different than a flask. The purifiedanalyte mixture contains solvents which are evaporated in an oxygen freeenvironment within the evaporation container 304 a. That is, theevaporation container 304 a can be filled with the inert gas (e.g.,nitrogen N₂) via a nozzle 308 a. The nozzle 308 a can be disposed incombination with a cap (not shown) inserted within the opening of theevaporation container 304 a, while an exhaust aperture in the cap (notshown) allows the high velocity flow of inert nitrogen gas (N₂) to movethe solvent within the container 304 a and promote evaporation.

In addition to movement of the solvent within the evaporation container304 a, the evaporation container 304 a can be heated to increase therate of evaporation. The container 304 a can be continuously purged withnitrogen to protect the analyte from oxidation. To protect lightsensitive analytes from select wavelengths of ultraviolet light, UVprotected polycarbonate doors can cover chambers 100 and 300.

In FIGS. 2 and 4 , the ducting from the heater H can be bifurcated suchthat a flow of heated air can be directed to both the reaction vessel104 a in the reaction chamber 100 and the evaporation container 304 a inthe evaporation chamber 300. Temperature sensors T1, T2, ST, located inthe reaction and evaporation chambers 100, 300, provide temperaturesignals to the processor 20. These signals are indicative of theinstantaneous temperatures within each of the chambers 100, 300 andwithin each of the reaction vessels 104 a, 104 b, 104 c, 104 d and eachof the evaporation containers 304 a, 304 b, 304 c, and 304 d. Theprocessor 20 can compare these signals to predefined temperature valuesstored in processor memory. The processor 20 evaluates the difference orerror signal between the stored temperature value and theactual/instantaneous temperature to raise or lower the temperature inthe respective chambers 100, 300 and/or reaction vessels 104 a, 104 b,104 c, 104 d and evaporation containers 304 a, 304 b, 304 c, and 304 d.

Temperature sensors T1, T2, and ST can be located in various locationswithin the analyte extractor 10 for the purpose of mapping thetemperature in the reaction and evaporation chambers 100, 300. Withrespect to the reaction chamber 100, the described embodiment shows atemperature sensor T1 to determine the temperature within the chamber100 while temperature sensor ST measures the temperature in each of theupper end caps to obtain a temperature reading from within each of thereaction vessels 104 a, 104 b, 104 c, 104 d. While these locationsprovide a reasonably accurate picture of the temperature within thereaction chamber 100 and within the vessels 104 a, 104 b, 104 c, 104 d,it will be understood that other locations may provide more direct oraccurate temperature measurements.

For example, in one alternate embodiment, a thermocouple can be attachedto the reaction vessel column 106 a of each of the vessels 104 a, 104 b,104 c, 104 d such that the temperature of the sample mixture can bemeasured within the respective vessels 104 a, 104 b, 104 c, 104 d. Thismay be done assuming, of course, that the borosilicate glass has asufficiently low R (resistivity) value and does not function as aninsulator. In yet another embodiment, a temperature sensor orthermocouple may be integrated within the plastic reaction vessel base110 a of each of the vessels 104 a, 104 b, 104 c, 104 d such thattemperature can be measured at the bottom of the respective vessels 104a, 104 b, 104 c, 104 d.

The fluid reservoirs R_(L1), R_(L2), R_(L3), R_(L4) may contain one ormore strong basic or acidic fluids, such as potassium hydroxide (KOH) orhydrochloric acid (HCl). Alternatively, the reservoirs R_(L1), R_(L2),R_(L3), R_(L4) may contain one or more solvents including, water (H₂O),ethanol (CH₃CH₂OH) and hexane (CH₃(CH₂)₄CH₃). Flow from the reservoirsR_(L1), R_(L2), R_(L3), R_(L4), and/or from the nitrogen supply may besupplied or activated by the external pumps P and/or controlled by oneor more valves V and/or flow meters M. In addition to the apertures 112a for accommodating fluid or gaseous flow, the reaction vessel cap 108 amay include at least one aperture for accepting pressure sensor SP.

The processor or controller 20 can be responsive to the temperature,pressure, and liquid sensor signals ST, SP, SL provided by each of thesesensors for changing the temperature, pressure, and flow within thereaction chamber 100, purification chamber 200, and evaporation chamber300. With respect to the temperature in the reaction chamber 100, analternate or second temperature sensor T1 (see FIG. 2 ) may be disposedin the reaction chamber 100 rather than through the reaction vessel cap108 a of the reaction vessel 104 a. The temperature in the reactionchamber 100 may be varied by controlling the output of the heater H andthe blower B. Accordingly, the processor 20 can be responsive totemperature signals from one or more temperature sensors.

Temperature sensor T1 can vary or change the output of the heat source Halong with the flow of the blower B. In one embodiment, a heat exchangercan be connected to the heater H and the blower can direct air over theheat exchanger to create heated air. It will be appreciated that theflow of heated air can be bifurcated such that while performing orcausing the reaction, some or all of the heated flow Hs can be directedto the reaction chamber 100 and, during evaporation of the liquid(s)contained in the sample, some or all of the flow HE can be directed tothe evaporation chamber 300. Consequently, the processor 20 may directthe flow from the heater H to either of chambers 100, 300 via abifurcated duct (BD). The processor 20 may be responsive to the pressuresignals to increase the pressure of the nitrogen gas (N₂) during thereaction to improve or increase the flow rate through of the reactionvessel drain 116 a. This can also serve as a method to inject nitrogengas (N₂) into the subsequent purification chamber 200, following thereaction in the reaction chamber 100.

Designing an automated system and method was a complex endeavorinvolving a series of inventive steps that were not obvious at the startof the project. A number of significant difficulties and challenges wereovercome to develop an instrument that performed automatically.

The reactions necessary to chemically release the analyte produces areaction mixture that is not always compatible with the next process.For example, the requirements for conditioning a SPE (solid phaseextraction) column are not typically compatible with a reaction mixturedesigned to chemically release the analyte. The passage of the analytefrom the reaction chamber, with both solid and liquid fractions, was notcompatible with a valve function necessary to transfer the analyte tothe next step. The solution was to carry out the reaction prior to, orabove, filtration so that only the liquid would pass through undercertain conditions. It was then discovered that changes to the reactionand a specialized filtration design was required. More specifically,unique filter designs, special mixing configurations and changes insolutions were required.

For example, the solution that passed through the filter contained acomplex mixture of the analyte and contaminants in an aqueous andorganic solvent solution. In order to isolate the analyte, an SPE columnwas employed. The stationary phase of the SPE was capable of retainingthe contaminants, water and other polar solvents, while allowing thenon-polar solvents (e.g., hexane) to elute the analyte for transfer tothe evaporation chamber. The resulting system included a reaction vesselhaving a bottom portion configured to be detachably released tofacilitate filter removal/replacement and sample introduction.Furthermore, the valve system was developed that facilitated transfer ofsolution to the next chamber or to waste. Finally, an SPE column wasemployed for purification, which communicated with a flask in anevaporation chamber that removed the solvent by nitrogen gas togetherwith a directed heat input.

Examples of Analyte Extraction

Vitamins

The analyte extractor 10 of the present disclosure is capable ofextracting analytes from complex matrices. One example is that of theextraction of vitamins A and E from infant formula. Infant formula canbe reconstituted with water, after which a sub-sample (aliquot) isweighed in the reaction vessels 104 a, 104 b, 104 c and 104 d, alongwith a combination of antioxidants. Each of the reaction vessels 104 a,104 b, 104 c and 104 d can be subsequently assembled into the reactionchamber 100. The reaction vessel cap 108 a, 108 b, 108 c, 108 d for eachcan be combined with the respective reaction vessel 104 a, 104 b, 104 c,104 d (i.e., effecting a fluid-tight seal with each of the reactionvessels 104 a, 104 b, 104 c, 104 d via the downward force applied by themounting bracket) once the reaction vessels 104 a, 104 b, 104 c, 104 dis placed on the instrument 10. The following processes areautomatically controlled by the processor 20: addition of saponificationsolutions (KOH and ethanol), mixing and heating to 75° C. for 30minutes, the addition of water, cooling to 60° C., passing the reactionmixture through the filter and allowing the liquid to pass into the SPEcolumn containing diatomaceous earth, eluting vitamin A and E from theSPE column with hexane (leaving the contaminants behind) and passingvitamins into the round bottom flasks in the evaporation chamber 300,the solvent is then evaporated by a vigorous flow of nitrogen and a heatsource focused on the bottom of the flask. The isolated oils containingvitamins A and E are manually re-dissolved in hexane and injected intoan HPLC for quantitation.

Total Fat Analysis

Another example is that of total fat analysis, through acid hydrolysis.The analyte extractor 10 recovers total fat by combining the digestion(HCl) and extraction processes in the reaction chamber 100 with theseparation capabilities of SPE. Ethanol can be used to displace theresidual water and bridge the polarity gap with hexane, allowing thehexane to penetrate the sample residue and filter, ultimately dissolvingthe fat. The constant agitation coupled with heated solvent greatlyenhances extraction ability. The SPE column binds the aqueous/ethanolicsolvent and components and allows the hexane to elute with the fat. Thisselective capability of the SPE allows the analyte extractor 10 tobypass the traditional drying step of the hydrolyzed sample such thatthe total fat analysis can be performed in a single device/instrument.

The steps involved for analysis of total fat begins with samplebreakdown in the reaction vessel 104 a. Before the sample is added, theselective, multi-layered reaction vessel filter 140 a can be placed inthe reaction vessel 104 a over the reaction vessel drain 116 a. Thereaction vessel filter 140 a comprises a combination of rigid andflexible layers which provide structural and loft benefits. Loftprevents the sample from clogging the filter during filtration, whilethe rigidity of the reaction vessel filter 140 a prevents it from movingunder the reaction vessel column 106 a. The sample can be then added andreassembled into the mounting bracket within the reaction chamber 100.In a total fat analysis, hydrochloric acid (HCl) can be contained in oneof the reservoirs R_(L2), R_(L3), R_(L4) and can be automatically addedinto the reaction vessel 104 a.

Enhanced by continuous mixing, the sample can be heated in the HClsolution to release the bound fat. Once the process is complete, theaqueous solution can be filtered to waste through the shuttle valve 150.By mixing and heating the sample in the reaction chamber 100, chemicalbreakdown of the sample can be optimized, and fat completely releasedfrom the sample matrix. The chemical breakdown also reduces theformation of gelatinous materials which can clog a filter. Inasmuch asthe chemical bonds are broken and contaminants are removed, the analyteextractor 10 can filter large samples through a relatively small filterallowing only the aqueous solution to pass.

The analyte extractor 10 bypasses the drying step by the integration ofthe SPE column. Rather than drying the sample, as discussed in theBackground section of this disclosure, the analyte extractor 10automatically adds solvents (e.g., ethanol and hexane) to the sampleresidue remaining on the reaction vessel filter 140 a. The hydrophilicnature of the ethanol combines with the water to make a new solvent thatcan be compatible with the hexane enabling the hexane to extract thefat. After extracting the wet residue with solvent, the extractedsolvent contains a dissolved mixture of medium-polarity substances alongwith the fat.

Therefore, the fat must be isolated from the nonfat components. In thepresent disclosure, this step can be performed by the SPE column, wherepolar and medium polar contaminants are separated from the non-polar,fat components. Furthermore, the SPE column interacts with the mixedsample solution allowing only non-polar solvents containing fat to exitthe SPE column into the evaporation flask. Once the solvent and fat haveentered the evaporation flask, the solvent is evaporated leaving onlyfat behind for further analysis.

The analyte extractor 10 is unique by comparison to other total fatanalysis methods. For example, the analyte extractor 10 can performtotal fat analyses with a single instrument which does not require aseparate drying step. This differentiates the analyte extractor 10 fromother extraction methods, which require the combination of at least twoinstruments and an oven drying step to accomplish total fat analysis.

It should be understood that various changes and modifications to theembodiments described herein will be apparent to those skilled in theart. Such changes and modifications can be made without departing fromthe spirit and scope of the present disclosure and without diminishingits intended advantages. It is therefore intended that such changes andmodifications be covered by the appended claims.

Although several embodiments of the disclosure have been disclosed inthe foregoing specification, it is understood by those skilled in theart that many modifications and other embodiments of the disclosure willcome to mind to which the disclosure pertains, having the benefit of theteaching presented in the foregoing description and associated drawings.It is thus understood that the disclosure is not limited to the specificembodiments disclosed herein above, and that many modifications andother embodiments are intended to be included within the scope of theappended claims. Moreover, although specific terms are employed herein,as well as in the claims which follow, they are used only in a genericand descriptive sense, and not for the purposes of limiting the presentdisclosure, nor the claims which follow.

The invention claimed is:
 1. A system for extracting an analyte from asample, the system comprising: a reaction chamber comprising: a reactionvessel configured to receive and mix the sample with a reaction solutionto produce a reaction mixture, the reaction vessel including: a filterconfigured to retain insoluble components contained within the reactionmixture while passing soluble components of the reaction mixture; and areaction vessel drain configured to dispense the soluble components fromthe reaction mixture and a dissolved analyte from the reaction vessel; apurification chamber comprising: a purification vessel column configuredto receive the soluble components from the reaction mixture and thedissolved analyte from the reaction vessel drain, the purificationvessel column including: a selective sorbent disposed in thepurification vessel configured to retain contaminants from the solublecomponents of the reaction mixture and passing a purified analyte; and apurification vessel drain for dispensing the purified analyte from thepurification vessel; and an evaporation chamber comprising: anevaporation vessel configured to receive the purified analyte from thepurification vessel drain; and a heater configured to evaporate asolvent from the purified analyte.
 2. The system of claim 1, wherein thereaction vessel, the purification vessel, and the evaporation vessel arevertically aligned along an axis.
 3. The system of claim 1, wherein thereaction vessel further comprises a mixer comprising a stir bar and amagnetic driver configured to create a magnetic flux field for drivingthe stir bar about an axis.
 4. The system of claim 1, wherein thepurification vessel further comprises a diffuser for diffusing thesoluble components from the reaction mixture, including the dissolvedanalyte, received from the reaction vessel.
 5. The system of claim 1,wherein the purification vessel further comprises a selective sorbentcomposed from a solid phase filter material.
 6. The system of claim 5,wherein the solid phase filter material is selected from the groupconsisting of siliceous earth or diatomaceous earth.
 7. The system ofclaim 1, further comprising a blower for blowing a heated gas into oneof the evaporation and reaction chambers.
 8. A system for extracting ananalyte from a sample, the system comprising: a reaction chambercomprising a reaction vessel configured to receive the sample with areaction solution, separate insoluble components from a reaction mixtureand dispense soluble components, including a dissolved analyte, from thereaction mixture; a purification chamber comprising a purificationvessel configured to receive the soluble components, including thedissolved analyte, from the reaction vessel, separate contaminants fromthe soluble components and dispense a purified analyte from thepurification vessel; and an evaporation chamber comprising anevaporation vessel configured to receive the purified analyte from thepurification vessel.
 9. The system of claim 8, further comprising: aheater configured to evaporate a solvent from the purified analyte. 10.The system of claim 9, wherein the reaction vessel, the purificationvessel, and the evaporation vessel are vertically aligned along an axis.11. The system of claim 9, wherein the reaction vessel further comprisesa mixer comprising a stir bar and a magnetic driver configured to createa magnetic flux field for driving the stir bar about an axis.
 12. Thesystem of claim 9, wherein the reaction vessel is detachable.
 13. Thesystem of claim 9, wherein the purification vessel is detachable. 14.The system of claim 9, wherein the purification vessel further comprisesa selective sorbent composed from a solid phase filter material.
 15. Thesystem of claim 14, wherein the solid phase filter material is selectedfrom the group consisting of siliceous earth or diatomaceous earth. 16.The system of claim 9, further comprising a blower for blowing a heatedgas into one of the evaporation and reaction chambers.
 17. A method forextracting an analyte from a sample, the method comprising the steps of:mixing the sample with a reaction solution in a reaction vessel toproduce a reaction mixture, separating insoluble components from thereaction mixture; dispensing soluble components, including a dissolvedanalyte, from the reaction mixture, receiving the soluble components,including the dissolved analyte, into a purification vessel; separatingcontaminants from the soluble components; and dispensing a purifiedanalyte of the soluble component from the purification vessel into anevaporation vessel.
 18. The method of claim 17 further comprising thestep of: heating the purified analyte to evaporate a solvent from theevaporation vessel.
 19. The method of claim 17 further comprising thestep of: aligning the reaction, purification and evaporation vesselsalong an axis to allow gravity assisted flow from one vessel to anothervessel.
 20. The method of claim 17 further comprising the step of:blowing a heated gas into one of the reaction, purification andevaporation vessels.